Dental measuring instrument.



N0. 783,804. PATENTED FEBLZB, 1905 L. A. SMITH.

DENTAL MEASURING INSTRUMENT.

APPLIUATION FILED NOV. 26. 1904.

, guvznfo'a Witt luau llimii drains Patented February 28, 1905 PATENT idFiCtIi.

BPECIFICATION forming-part of Letters Patent No. 783,804, dated February'28, 1905. Application filed November 26, 1904. Serial No. 234,417.

-To m/lki whom, it may concern:

Be it known that l, Lmvnunou A. SMITH, a citizen of the United States of America, and a residentof Port Gibson, in the county of (liaiborne and State oi Mississippi, have invented certain new and useful improvements in Dental Measuring instruments, of which the following is a full, clear, and exact description.

The object of this invention is to provide a simple and inexpensive device by the use oi which the diameters oi teeth and the spaces between teeth may be accurately and quickly ascertained. This object is accomplished by the use of the device illustrated in the accomianying drawings; and theii'ivention consists in certain novel features oi the same, as will be hereinafter iirst fully described and then particularly pointed out in the appended claims.

in the drawings just mentioned, liigurel is a side elevation of an instrument constructed in accordance with myinvention. Fig. 2 is a longitudinal section of the sliding member, and Fig. 3 is a transverse section on the line 3 3 oi Fig. 1.

1n carryingout my invention i. employ a sta tionary member consisting oi a shank 1 and a jaw 2, rigidly secured to the end of the same. Mounted upon the shank is a sliding member which consists oi? a series of eyes or loops 3, a base or back 4:, and a jaw 5. The jaw is formed integral with or secured to the innermost loop, and the back or base extends through the several loops and lies against the shank of the stationary member. The base is secured to or formed integral with the innermost and central loops, and its end projects freely in the outer loop. Between the outer and the central loops a lug or :iulcrum-block 6 is formed on the back of the base, and over this lugor fulcrunrblock rests a spring 7, having itsopposite ends secured, respectively, to the central and outer loops. On the sides oi the shank are formed scales to mark the measurements taken by the instrument. The jaws are similar in construction, and consist of thin metal blades having straight sides tor a portion of their length, as indicated at 8, and between said straight portions and the shank of the instrument they are gradually increased in thickness, so as to impart the necessary rigidity and strength to the device.

The manner oi using the device will be readily understood. The loops encircling the shank are pushed toward the rigid jaw, so as to carry the sliding jaw close to the same, and the instrun'ient is then placed in the mouth oi. the patient and adj uste until the jaws bear iirmly against the opposite sides oi the tooth. The instrument then withdrawn, and the d iameter oi. the tooth will be denoted bythe scale on the shank between the jaws. Should it be desired to measure a space between teeth, the jaws are adjusted until the outer sides of the same bear lirmly against the sides oi the teeth at the opposite ends oi the space, after which the instrunumt is witlnlrawn and the measurenient read upon the scale on the side 01 the shank opposite theside used in the beioredescribed operation. it is to be noted that there are no set-screws or similar fastening devices employed to lock the jaws in their adjusted positions, so that the liability of injury to the mouth of the patient or the hands oi the operator from that source is obviated. The free end of the spring holds the outer loop against the shank with suiiicicnt force to bind it in an znljusted position, and the operation of the spring isz'uiceleratml and made certain by the provision oi the fulcrum block or lug which intensities the resilientaction of the sprin When the operator is applying the instrument, he presses against the outer loop with his linger, and thereby overcomes the force of the spring, so as to permit the sliding member to be moved along the shank, and when the desired adjustment has been attained it is necessary merely to release the pressure of the iinger, when the spring at once binds the loop against the shank so as to maintain the adjustment.

The device is obviously simple in its construction, and it constitutes an eilicient addition to the equipment of a dentist.

Having thus described my invention, what i claim, and desire to secure by Letters Pitt,- ent, is-

1. A dental measuring instrument consisting of a stationary member, and a sliding member having a series of loops iitting on said back, and a spring secured beyond said fulcrum-block, passing over the same and having its end secured to the loop in which the free end of the back plays.

In testimony whereof I have signed this specification in the presence of two attesting l Witnesses.

LAWRENCE A. SMITH. \Vitnesses:

JOHN MOCALEB MARTIN, 1 HENRY WV. M. DRAKE. 

